TUESDAY, Nov. 14, 2017 (HealthDay News) -- People with certain blood types are at increased risk for a heart attack from high levels of air pollution, a new study finds.

Specifically, people with coronary artery disease who have A, B or AB blood types are more likely than those with the O blood type to have a heart attack when exposed to high levels of small particulate PM2.5 air pollution. That is described by the U.S. Environmental Protection Agency as inhalable particles with a diameter of 2.5 micrometers or smaller.

Most people won't have a heart attack unless they have coronary artery disease. And even then it's not inevitable, the researchers said in a news release from the Intermountain Medical Center Heart Institute in Salt Lake City.

"You have to have other characteristics for coronary disease to progress to a heart attack," lead investigator Benjamin Horne, a clinical epidemiologist at the institute, said in the news release.

"The association between heart attacks and pollution in patients with non-O blood isn't something to panic over, but it is something to be aware of," he added.

The study was to be presented Tuesday at the American Heart Association's annual meeting, in Anaheim, Calif.

Research presented at meetings should be considered preliminary because it has not been subjected to the rigorous scrutiny given to research published in medical journals.

More information

The American Heart Association has more on the health effects of air pollution.